COX-2 Selectivity Index Research Articles

Novel 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene analogues as selective COX-2 inhibitors: Design, synthesis, anti-inflammatory evaluation, and molecular docking studies

A series of 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene derivatives were synthesized and evaluated for in vitro COX inhibitory potential. Within the series, compounds 4a, 4j, 4k, and 4q were identified as potential and selective COX-2 inhibitors with COX-2 IC50 in 0.31–1.40µM range; COX-2 selectivity index (SI)=48.8–183.8 range and they showed percent PGE-2 inhibitory activity in the range of 25.4–46.9. Further, compounds 4a, 4j, 4k and 4q displayed potent anti-inflammatory activity with percentage rise in paw volume ranging from 21.1–30.5 at 180min, while celecoxib demonstrated 19.6 percentage rise at the same dose at 180min in carrageenan-induced rat paw edema assay. Cell viability via MTT assay showed no cytotoxicity up to 80µM concentrations. Molecular docking study of potent compounds in the series showed Gscore comparable to celecoxib with similar binding orientation for the COX-2 active site which also corroborates the observed in vitro COX-2 inhibition.

Synthesis of new pyrazolo[3,4-d]pyrimidine derivatives and evaluation of their anti-inflammatory and anticancer activities.

This study reports the synthesis of two series of new purine bioisosteres comprising a pyrazolo[3,4-d]pyrimidine scaffold linked to piperazine moiety through different amide linkages. The newly synthesized compounds were evaluated for anticancer activity against four cell lines (MDA-MB-231, MCF-7, SF-268, B16F-10) and cyclooxygenase (COX-2) protein expression inhibition in lipopolysaccharide (LPS)-activated rat monocytes. The results revealed that most of the synthesized compounds showed moderate-to-high cytotoxic activity against at least one cell line, with compound 10b being the most active against all used cell lines (IC50 values 5.5-11μg/ml) comparable to cisplatin. In addition, six of these compounds (7b, 10a-d, and 12c) demonstrated inhibition of LPS-induced COX-2 protein expression at low concentration (25μg/ml) as compared to the control non-stimulated cells and showed a COX-2 selectivity index range comparable to diclofenac sodium. The overall results indicate that many of these pyrazolopyrimidine derivatives possess in vitro anti-inflammatory and anticancer activities at varying doses, and the most active compounds will be subjected to in vivo pharmacological evaluation.

Synthesis, Cyclooxygenase Inhibition, Anti‐Inflammatory Evaluation, and Ulcerogenic Liability of New 1,3,5‐Triarylpyrazoline Derivatives Possessing a Methanesulfonyl Pharmacophore

A new series of 1,3,5-triarylpyrazolines 13a-l was synthesized and all prepared compounds were evaluated for their in vitro COX-1/COX-2 inhibitory activity and in vivo anti-inflammatory activity. All test compounds were more selective for the COX-2 isozyme and showed good in vivo anti-inflammatory activity. Compound 13h was the most COX-2 selective compound (COX-2 selectivity index (SI) = 10.23) and the most potent anti-inflammatory derivative (ED50 = 60.1 µmol/kg) in comparison with celecoxib (COX-2 SI = 9.29 and ED50 = 81.4 µmol/kg). All screened compounds were less ulcerogenic (ulcer indexes (UI) = 0.33-1.33) than aspirin (UI = 2.33) and comparable to celecoxib (UI = 0.33).

Synthesis, anti-inflammatory, analgesic, COX-1/2 inhibitory activities and molecular docking studies of substituted 2-mercapto-4(3H)-quinazolinones

A new series of 2-substituted mercapto-4(3H)-quinazolinone 1–26 were synthesized and assessed for in vivo anti-inflammatory and analgesic activities and in vitro inhibition of cyclooxygenase COX-1/COX-2.A new series of 2-substituted mercapto-4(3H)-quinazolinone 1–26 were synthesized and assessed for in vivo anti-inflammatory and analgesic activities. The potent anti-inflammatory compounds were subjected to in vitro cyclooxygenase COX-1/COX-2 inhibition assays.Compounds 1, 3, 5, 11, 12, 13, 15, 17, and 25 exhibited potent anti-inflammatory effects, with half-maximal effective dose (ED50) values of 65.7–102.4 mg/kg, (0.16–0.36 mmol/kg), and strong analgesic activities, with ED50 values of 33.3–104.6 mg/kg, (0.07–0.34 mmol/kg). These values were compared with those of diclofenac sodium [ED50 values: 112.2 and 100.4 mg/kg, (0.35 and 0.31 mmol/kg)], and celecoxib [ED50 values: 84.3 and 71.6 mg/kg (0.22 and 0.19 mmol/kg)], respectively as reference drugs. Compounds 1, 11, 12, 13, 15, 17, and 25 exhibited effective COX-2 inhibitory activity, with half-maximal inhibitor concentration (IC50) values of 0.70–2.0 μM and selectivity index (SI) values of more than 50–142.9 compared with celecoxib as reference drugs (IC50 = 0.30 μM and COX-2 SI: >333). Potent COX-2 inhibitors, i.e., compounds 15, 11, and 17 were docked into the binding site pockets of COX-1 and COX-2. These compounds exhibited strong interactions at the COX-2 binding site and poor interactions at COX-1 active site pocket.

Synthesis, anti-inflammatory, analgesic and COX-1/2 inhibition activities of anilides based on 5,5-diphenylimidazolidine-2,4-dione scaffold: Molecular docking studies

The design, synthesis and pharmacological activities of a group of 5,5-diphenylimidazolidine-2,4-dione bearing anilide, phenacyl and benzylidene fragments 2–27 were reported. The prepared 5,5-diphenylimidazolidine-2,4-dione derivatives were evaluated in vivo for anti-inflammatory, analgesic activities and in vitro for COX-1/2 inhibition assay. Among the tested compounds, derivatives 5, 9, 10, 13, and 14 showed significant and potent anti-inflammatory and analgesic activities almost equivalent to reference drug celecoxib. In COX-1/2 inhibition assay, compounds 5, 9, 10 and 14 showed high COX-2 inhibitory activity (IC50 = 0.70 μM, 0.44 μM, 0.61 μM and 0.41 μM; respectively) and selectivity index (SI) range of 142–243 comparable to celecoxib [COX-2 (SI) > 333]. These potent COX-2 inhibitors 9, 10, 13, and 14 were docked into the active site pocket of COX-2 to explore the binding mode and possible interactions of these ligands.

Design, Synthesis and Biological Evaluation of4-(Imidazolylmethyl)-2-(4-methylsulfonyl phenyl)-Quinoline Derivatives as Selective COX-2 Inhibitors and In-vitro Anti-breast Cancer Agents.

A new group of 4-(Imidazolylmethyl)quinoline derivatives possessing a methylsulfonyl COX-2 pharmacophore at the para position of the C-2 phenyl ring were designed and synthesized as selective COX-2 inhibitors and in-vitroanti breast cancer agents. In-vitro COX-1 and COX-2 inhibition studies showed that all the compounds were potent and selective inhibitors of the COX-2 isozyme with IC50 values in the potent range 0.063-0.090 µM, and COX-2 selectivity indexes in the 179.9 to 547.6 range. Molecular modeling studies indicated that the methylsulfonyl substituent can be inserted into the secondary pocket of COX-2 active site for interactions with Arg(513). Cytotoxicity of quinolines 9a-e against human breast cancer MCF-7 and T47D cell lines were also evaluated. All the compounds 9a-e were more cytotoxic against MCF-7 cells in comparison with those of T47D which express aromatase mRNA less than MCF-7 cells.The data showed that the increase of lipophilic properties of substituents on the C-7 and C-8 quinoline ring increased their cytotoxicity on MCF-7cells andCOX-2 inhibitory activity. Among the quinolines 9a-e, 4-((1H-Imidazol-1-yl)methyl) 7,8,9,10-tetrahydro-2-(4-methylsulfonylphenyl)-benzo[h]quinoline (9d)was identified as the most potent andselective COX-2inhibitor as well as the most cytotoxic agent against MCF-7 cells.

Design, Synthesis and Biological Evaluation of New 1, 4-Dihydropyridine (DHP) Derivatives as Selective Cyclooxygenase-2 Inhibitors.

As a continuous research for discovery of new COX-2 inhibitors, chemical synthesis, in vitro biological activity and molecular docking study of a new group of 1, 4-dihydropyridine (DHP) derivatives were presented. Novel synthesized compounds possessing a COX-2 SO2Me pharmacophore at the para position of C-4 phenyl ring, different hydrophobic groups (R1) at C-2 position and alkoxycarbonyl groups (COOR2) at C-3 position of 1, 4-dihydropyridine, displayed selective inhibitory activity against COX-2 isozyme. Among them, compound 5e was identified as the most potent and selective COX-2 inhibitor with IC50 value of 0.30 μM and COX-2 selectivity index of 92. Molecular docking study was performed to determine probable binding models of compound 5e. The study showed that the p-SO2Me-phenyl fragment of 5e inserted inside secondary COX-2 binding site (Arg(513), Phe(518), Gly(519), and His(90)). The structure-activity relationships acquired reveal that compound 5e with methyl and ethoxycarbonyl as R1 and COOR2 substitutions has the necessary geometry to provide selective inhibition of the COX-2 isozyme and it can be a good basis for the development of new hits.

Structure-based design of phthalimide derivatives as potential cyclooxygenase-2 (COX-2) inhibitors: anti-inflammatory and analgesic activities.

A group of 30 cyclic imides (1-10a-c) was designed for evaluation as a selective COX-2 inhibitor and investigated invivo for anti-inflammatory and analgesic activities. Compounds 6a, 6b, 7a and 7b exhibit optimal COX-2 inhibitory potency (IC50=0.18, 0.24, 0.28 and 0.36μM; respectively) and selectivity index (SI) range of 363-668. Invitro COX-1/COX-2 inhibition structure-activity studies identified compound 6a as a highly potent (IC50=0.18μM), and an extremely selective [COX-2 (SI)=668] comparable to celecoxib [COX-2 (SI)>384], COX-2 inhibitor that showed superior anti-inflammatory activity (ED50=54.0mg/kg) relative to diclofenac (ED50=114mg/kg).Molecular Docking study of the synthesized compound 6a into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor. Docking study showed that the methoxy moeities of 6a inserted deep inside the 2°-pocket of the COX-2 active site, where the O-atoms of such groups underwent an H-bonding interaction with His(90) (3.02Å), Arg(513) (1.94, 2.83Å), and Gln(192) (3.25Å).

Design, Synthesis, and Biological Evaluation of New 2-Phenyl-4H-chromen-4-one Derivatives as Selective Cyclooxygenase-2 Inhibitors.

In order to develop new selective COX-2 inhibitors, a new series of 2-phenyl-4H-chromen-4-one derivatives possessing a methylsulfonyl pharmacophore group at the para position of the C-4 phenyl ring were designed, synthesized, and evaluated for cyclooxygenase-2 inhibitory activity. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) as a potent COX-2 inhibitor (IC50 = 0.07 μM) with a high COX-2 selectivity index (SI = 287.1) comparable to the reference drug celecoxib (COX-2 IC50 = 0.06 μM; COX-2 SI = 405). A molecular modeling study where 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) was docked into the active site of COX-2 showed that the p-MeSO2 substituent on the C-4 phenyl ring was well-oriented in the vicinity of the COX-2 secondary pocket (Arg513, Val523, and His90) and the carbonyl group of the chromene ring could interact with Ser530. The structure-activity data acquired indicated that the nature and size of the substituent on the C-3 chromene scaffold are important for COX-2 inhibitory activity. Our results also indicated that the chromene moiety constitutes a suitable template to design new COX-2 inhibitors.

Synthesis, biological evaluation and docking analysis of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones as potential cyclooxygenase-2 (COX-2) inhibitors

As a part of our continued efforts to discover new COX inhibitors, a series of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones were synthesized and evaluated for in vitro COX inhibitory potential. Within this series, seven compounds (3a–d, 3h, 3k and 3q) were identified as potential and selective COX-2 inhibitors (COX-2 IC50’s in 1.79–4.35μM range; COX-2 selectivity index (SI)=6.8–16.7 range). Compound 3b emerged as most potent (COX-2 IC50=1.79μM; COX-1 IC50 >30μM) and selective COX-2 inhibitor (SI >16.7). Further, compound 3b displayed superior anti-inflammatory activity (59.86% inhibition of edema at 5h) in comparison to celecoxib (51.44% inhibition of edema at 5h) in carrageenan-induced rat paw edema assay. Structure–activity relationship studies suggested that N-phenyl ring substituted with p-CF3 substituent (3b, 3k and 3q) leads to more selective inhibition of COX-2. To corroborate obtained experimental biological data, molecular docking study was carried out which revealed that compound 3b showed stronger binding interaction with COX-2 as compared to COX-1.

Synthesis, biological evaluation of certain pyrazolo[3,4-d]pyrimidines as novel anti-inflammatory and analgesic agents

In the present study, a series of pyrazolo[3,4-d]pyrimidin-4(5H)-ones linked at 5-position to thiazoline or thiazolidinone ring systems through imino linkage (5–8) was designed and synthesized. The compounds were assessed for their anti-inflammatory activity and analgesic in vivo. Also, their ability to inhibit ovine COX-1/COX-2 isozymes was evaluated using in vitro cyclooxygenase (COX) inhibition assay. The newly synthesized compounds 7, 8d, and 8e showed potent anti-inflammatory and analgesic activity. Moreover, compound 7 displayed preferential COX-2 inhibitory potency (IC50 = 0.53 µM and COX-2 selectivity index = 10.07) which is more potent than the standard drug meloxicam. Interestingly, the tested compounds showed excellent gastrointestinal safety profile and were well tolerated by experimental animals with high safety margins than the reference drug meloxicam.

Design, synthesis and docking studies of 2-benzoxazolinone-based 1,2,4-triazoles as proinflammatory cytokine inhibitors

A library of 20 novel benzoxazolinone-based 1,2,4-triazoles has been synthesised and screened for their in vivo anti-inflammatory and antinociceptive activities. The compound 18e exhibited potent anti-inflammatory activity with 68.75 and 55.20 % inhibition in comparison to indomethacin which showed 65.62 and 60.41 % inhibition after 3 and 5 h, respectively. The five active compounds, i.e. 2a and 17e–20e showing significant in vivo anti-inflammatory activity have been screened for their in vivo COX-2, TNF-α, IL-1β and NO inhibitory activities. The COX-2 selectivity index of 17e was found to be 42.30 and thereby showing a high selectivity towards COX-2 inhibition. In silico molecular docking studies have been done in order to get an insight into the binding modes of these molecules with TNF-α protein. The compound 20e exhibited potent antinociceptive activity with 56.70 % inhibition of analgesia. The compounds 2a and 17e–20e did not exhibit any gastric ulceration.

Synthesis, biological evaluation, and docking analysis of a novel family of 1-methyl-1H-pyrrole-2,5-diones as highly potent and selective cyclooxygenase-2 (COX-2) inhibitors

As a continuous research for discovery of new COX-2 inhibitors, we present the simple chemical synthesis, in vitro biological screening, and molecular docking study of 1H-pyrrole-2,5-dione derivatives. New synthetic compounds were evaluated for the inhibitory activities on LPS-induced PGE2 production in RAW 264.7 macrophage cells as well as the COX-1 and COX-2 inhibitory potency. Among them, compound 9d (MPO-0029) was identified as more potent and selective COX-2 inhibitor [PGE2 IC50=8.7nM, COX-2 IC50=6.0nM; COX-2 selectivity index (SI)=>168] than celecoxib. Molecular docking experiments were further performed against COX-2 and COX-1 isozymes to determine their probable binding models. Results of molecular docking studies revealed that compound 9d (MPO-0029) has stronger binding interaction with COX-2 than with COX-1 isozyme, and provided successfully complementary theoretical support for the obtained experimental biological data.

Design, synthesis and biological evaluation of 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives as selective cyclooxygenase-2 inhibitors.

A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity.

Synthesis, Anti-Inflammatory and Anti- Nociceptive Activities and Cytotoxic Effect of Novel Thiazolidin-4-ones Derivatives as Selective Cyclooxygenase (COX-2) Inhibitors.

Nowadays, COX - 2 inhibitors such as valdecoxib are removed from the market because of their cardiovascular toxicity and their potential to increase the risk of strokes. In response to this, medicinal chemists have attempted to synthesize new classes of COX-2 Inhibitors. In this study, three novel analogues of thiazolidin-4-ones derivatives 2a-c were synthesized. The ability of these compounds to inhibit ovine COX-1 and COX-2 (0.2- 0.8 µM) was determined using a colorimetric method. The cytotoxic effect of the synthesized compounds (25-100 M) was also investigated by measuring their cytotoxicity against Caco-2 and MCF-7 cell lines using MTT assay. Cell apoptosis was determined by flow cytometry. Writhing test (7.5-75 mg/kg) was used to examine the antinociceptive effects in mice. The effect of the analogues against acute inflammation (7.5-75 mg/kg) was also studied using xylene-induced ear edema test in mice. The synthesized compounds showed a weak capacity to inhibit the proliferation of Caco-2 and MCF-7 cell lines. The COX-2 inhibition potency and selectivity index for test compounds 2a-b were as follows; celecoxib > 2b > 2a. On the other hand, all three analogues exhibited strong antinociceptive activity against acetic acid-induced writhing. The anti-inflammatory and antinociceptive effects of the analogues were markedly more than positive control, celecoxib. This study demonstrates that the antinociceptive and anti-inflammatory activity profiles exhibited by the novel synthesized compounds are independent from their COX-2 inhibitory potencies. The found antinociceptive and anti-inflammatory effects can be caused by interaction with other target; independent from COX-2. Accordingly, the compounds 2a-c could serve as lead compounds to develop novel anti-inflammation and antinociceptive drugs.

Fluorophore‐Labeled Cyclooxygenase‐2 Inhibitors for the Imaging of Cyclooxygenase‐2 Overexpression in Cancer: Synthesis and Biological Studies

A group of cyclooxygenase-2 (COX-2)-specific fluorescent cancer biomarkers were synthesized by linking the anti-inflammatory drugs ibuprofen, (S)-naproxen, and celecoxib to the 7-nitrobenzofurazan (NBD) fluorophore. In vitro COX-1/COX-2 inhibition studies indicated that all of these fluorescent conjugates are COX-2 inhibitors (IC₅₀ range: 0.19-23.0 μM) with an appreciable COX-2 selectivity index (SI≥4.3-444). In this study the celecoxib-NBD conjugate N-(2-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)amino)ethyl)-4-(5-(p-tolyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl)benzenesulfonamide, which displayed the highest COX-2 inhibitory potency and selectivity (COX-2 IC₅₀ =0.19 μM; SI=443.6), was identified as an impending COX-2-specific biomarker for the fluorescence imaging of cancer using a COX-2-expressing human colon cancer cell line (HCA-7).

Synthesis and biologic evaluation of new 3-phenoxyazetidin-2-one derivatives as selective cyclooxygenase-2 inhibitors

A new series of 3-phenoxyazetidin-2-ones (β-lactams) were designed and synthesized for the evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 inhibition studies showed that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the 0.054–0.095 μM range, and COX-2 selectivity indexes in the 228.47–355.6 range. Among the synthesized compounds, 1-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)-3-phenoxyazetidin-2-one (4j) possessing methoxy group at the para position of N-1 phenyl ring exhibited the highest COX-2 inhibitory selectivity and potency even more potent than the reference drug celecoxib. Molecular modeling studies indicated that the methylsulfonyl pharmacophore group can be inserted into the secondary pocket of COX-2 active site.

Synthesis and evaluation of fluorobenzoylated di- and tripeptides as inhibitors of cyclooxygenase-2 (COX-2)

A series of fluorobenzoylated di- and tripeptides as potential leads for the development of molecular probes for imaging of COX-2 expression was prepared according to standard Fmoc-based solid-phase peptide synthesis. All peptides were assessed for their COX-2 inhibitory potency and selectivity profile in a fluorescence-based COX binding assay. Within the series of 15 peptides tested, cysteine-containing peptides numbered 7, 8, 11 and 12, respectively, were the most potent COX-2 inhibitors possessing IC50 values ranging from 5 to 85μM. Fluorobenzoylated tripeptides 7 and 8 displayed some COX-2 selectivity (COX-2 selectivity index 2.1 and 1.6), whereas fluorobenzoylated dipeptides 11 and 12 were shown not to be COX-2 selective. Fluorbenzoylated tripeptide FB-Phe-Cys-Ser-OH was further used in molecular modeling docking studies to determine the binding mode within the active site of the COX-2 enzyme.

N-1 and C-3 substituted indole Schiff bases as selective COX-2 inhibitors: Synthesis and biological evaluation

A group of N-1 and C-3 disubstituted-indole Schiff bases bearing an indole N-1 (R′=H, CH2Ph, COPh) substituent in conjunction with a C-3 –CHN–C6H4–4-X (X=F, Me, CF3, Cl) substituent were synthesized and evaluated as inhibitors of cyclooxygenase (COX) isozymes (COX-1/COX-2). Within this group of Schiff bases, compounds 15 (R1=CH2Ph, X=F), 17 (R1=CH2Ph, X=CF3), 18 (R1=COPh, X=F) and 20 (R1=COPh, X=CF3) were identified as effective and selective COX-2 inhibitors (COX-2 IC50’s=0.32–0.84μM range; COX-2 selectivity index (SI)=113 to >312 range). 1-Benzoyl-3-[(4-trifluoromethylphenylimino)methyl]indole (20) emerged as the most potent (COX-1 IC50 >100μM; COX-2 IC50=0.32μM) and selective (SI >312) COX-2 inhibitor. Furthermore, compound 20 is a selective COX-2 inhibitor in contrast to the reference drug indomethacin that is a potent and selective COX-1 inhibitor (COX-1 IC50=0.13μM; COX-2 IC50=6.9μM, COX-2 SI=0.02). Molecular modeling studies employing compound 20 showed that the phenyl CF3 substituent attached to the CN spacer is positioned near the secondary pocket of the COX-2 active site, the CN nitrogen atom is hydrogen bonded (N⋯NH=2.85Å) to the H90 residue, and the indole N-1 benzoyl is positioned in a hydrophobic pocket of the COX-2 active site near W387.

Novel selective Cox-2 inhibitors induce apoptosis in Caco-2 colorectal carcinoma cell line

The cyclooxygenase-2 (COX-2) inhibitors including celecoxib inhibit cell growth and induce apoptosis in cancer cells. As COX-2 is over expressed in solid tumors such as colorectal cancer, it can be a suitable target for cancer treatment studies. In this study we designed and synthesized 4,5-bisaryl imidazolyl imidazoles as novel COX-2 inhibitors and evaluated their apoptosis inducing activities. The ability of our synthetic compounds to inhibit ovine COX-1 and COX-2 was determined using a colorimetric method. The effects of these COX-2 inhibitors and celecoxib on the proliferation of Caco-2 cells were evaluated by MTT assay. Cell apoptosis was determined by flow cytometry and DNA fragmentation assay. cDNA microarray technique was used to evaluate the effects of these synthetic compounds on 112 genes involved in apoptosis pathways. The expression of five apoptosis-related genes Bak-1, Bcl-x, BIRC (Survivin), TNFSF10 and CASP3 were evaluated by quantitative real-time PCR. Among our synthetic compounds ( 3a– c), 4,5-bis(4-methoxyphenyl)-1H-imidazol-2-yl derivative (compound 3c) exhibited the highest COX-1/COX-2 selectivity index (SI = 262.9) and lowest growth inhibitory concentration (IC 50 = 21.20 μM). In addition, compounds 3a– c could up-regulate pro-apoptotic genes and down-regulate anti-apoptotic genes. So, these synthetic compounds seem to be inducers of apoptosis in Caco-2 cell line. This study indicates that 4,5-bisaryl imidazolyl imidazole is a suitable scaffold to design COX-2 inhibitors and 4,5-bis(4-methoxyphenyl)-1H-imidazol-2-yl derivative exhibited highly COX-2 inhibitory potency and selectivity even more than celecoxib. It seems that it could induce apoptosis in Caco-2 colorectal carcinoma cell line.